1. Field of the Invention
This invention pertains to a collection and filter unit for separating particulate matter from an air flow stream utilizing inertial separation and an impingement type filter mounted within a structure which reduces the dust loadings imposed on the impingement or porous media filter element.
2. Background Art
In the art of separation of particulate matter from flow streams of air and other gases a number of different apparatus have been developed utilizing inertial separation techniques as well as employing impingement or porous media type filter elements for separating relatively fine particles which remain airborne even after several stages of inertial or gravitational separation. For example, in air filter apparatus for various types of machinery such as compressors and engines the filter unit is normally relatively compact and mechanically simple with reliance being placed on porous media or impingement type filter elements for performing substantially all of the separation or filtering action. Accordingly, these elements are constructed as economically as possible so that they may be thrown away and replaced with new elements as needed.
However, in industrial applications where substantially continuous and sometimes heavy loadings of airborne particulate matter must be dealt with it is important to provide for collection and filtration apparatus which is capable of reducing the loadings on the porous media type filter elements as well as, in many applications, reclaiming the separated particulate matter. The continued emphasis on reducing air pollution from industrial activity of one type or another has made it highly desirable to develop dust collection and filtration apparatus which is suitable for substantially continuous operation in industrial environments without the necessity of frequent replacement of porous media filter elements or the like.
It is also desirable that collection and filtration apparatus for airborne particulate matter be provided which will reduce the loadings on the porous media filter elements and also is adapted to reclaim the airborne particles which, in some instances, have commercial value. The present invention represents an improvement in this general category of collection and filtration equipment for airborne dust or particulate matter and comprises an apparatus which is mechanically uncomplicated, effective in operation and adapted to be of modular construction to suit various applications where removal of particulate matter or dust from the environment is required.